WR Wide Ratio Tranny in a YZF

Jeepentj

I have a 2006 YZ450F and have read through the FAQ thread indicating the 2007 WR tranny will work in my bike. I'm very close to doing this but would like to hear from somebody who has actually done this.

If you've done this, can you let me know so I can ask you some questions about how it affected the bike in real world applications?

kskyles

i'm in the same situation....i'm looking to sell the WR and get a YZ, then do the tranny swap. anyone out there had any issues? has it been worth the money? a YZ with the WR transmission seems like the perfect desert bike.

kskyles

thanks for the thread reference, i read it right before posting. it's great to have the part numbers. looks like a straight-forward swap.

But the perfect desert bike would need a DC charging system capable of running a pair of HIDs, and an e-start, but not be more than 10 pounds heavier than a YZ.

i guess i should have said, it would be the perfect desert bike for me. i love the estart, but could live without it. i don't ride at night, so no need for lights...i'd like to try out a lighter bike that will actually turn. the WR is a fabulous bike, but my eye is starting to wander.....

Jeepentj

But the perfect desert bike would need a DC charging system capable of running a pair of HIDs, and an e-start, but not be more than 10 pounds heavier than a YZ.

Thanks Grayracer. It looks like the thread you linked to is the sticky I read. Unfortunately most of it talks about the theory of the mod or whether it's worth doing. I'm looking to chat with somebody who's actually done it on their bike for some firsthand experience.

grayracer513

Jeepentj

It's not theoretical in any way. The WR parts bolt directly in, and it's just a matter of whether you like the ratios or not. Ever ride a WR?

I guess "theory" isn't the right word because you're right, it's clearly possible to perform this swap. What I'd like to know is how the mod changes the power, feel and breadth of a YZF though. I have ridden a WR but didn't feel it had the snap I like (and have today) and was just a little too mellow. I presume in part this is due to the wider ratio tranny but hopefully more so it was due to the crank, cam, etc.

Frankly, if the tranny mod makes the bike feel like a WR, I'll skip it. WR's are great bike; just not what I'm looking for.

It's a chart comparing the two ratio sets. Think of it as two bicycle freewheels side by side. There's not a huge difference anywhere except for the 1-2 gap.

For example, in order to shift a YZ into 3rd with the engine pulling at 5500 rpm (the meaty part of the torque curve), you have to run the engine out to about 6700 in 2nd. With the WR ratios, would would need to rev it out to 7200 to accomplish the same thing.

The biggest difference in the set is how low 1st gear is, and the change to top speed in 5th. Whereas 8K in 1st with the YZ trans turns the rear wheel 33 MPH, with a WR low gear it's 24 mph. In 5th, 9K with a YZ trans will produce 76 mph with perfect traction, with the WR it runs up to 86. Operating RPM at 65 mph goes from 7000 down to around 6300.

gdbarr1976

I am not real sure why anyone would want to do this. Stock first gear on my 08 is plenty low for any woods riding and 5th is plenty fast. Well allmost stock 13/50. I am taking it to Baja and all I am doing is going to 15/48. I ran my 06 like that and you don't need anymore top end. As far as the spacing I have raced a 07wr and the gearing just is not a issue pro or con.

cowboyona426

I am not real sure why anyone would want to do this. Stock first gear on my 08 is plenty low for any woods riding and 5th is plenty fast. Well allmost stock 13/50. I am taking it to Baja and all I am doing is going to 15/48. I ran my 06 like that and you don't need anymore top end. As far as the spacing I have raced a 07wr and the gearing just is not a issue pro or con.

Come out west and twist through trees in a trail barely as wide as your handlebars and tell me the YZ 1st gear is low enough! Since I rarely am going anywhere 5th and pinned anways, I wonder about swapping just the WR 1st and 2nd in and leaving the rest alone... gray?

gdbarr1976

Come out west and twist through trees in a trail barely as wide as your handlebars and tell me the YZ 1st gear is low enough! Since I rarely am going anywhere 5th and pinned anways, I wonder about swapping just the WR 1st and 2nd in and leaving the rest alone... gray?

We've got a few tree's here in Alabama:ride:

It used to be that alot of the enduros around here were very tite survival runs. Not so much anymore it seems.

I would think that if you geared down much more you would start having other issues mainly overhearting from no air flow. If you get down to those speeds if it was me I would be looking for a 2 stroke. Kinda been thinking going that route myself.

grayracer513

I am not real sure why anyone would want to do this. Stock first gear on my 08 is plenty low for any woods riding and 5th is plenty fast. Well allmost stock 13/50. I am taking it to Baja and all I am doing is going to 15/48. I ran my 06 like that and you don't need anymore top end. As far as the spacing I have raced a 07wr and the gearing just is not a issue pro or con.

You should try some of the courses I run. Some of them work their way up through a rocky gorge and scale the rarely used backside of a mountain, then drop you out onto a dry lake. My YZ WILL go as fast as I want to on the lake bed, but I get very uncomfortable with running it at that speed for 2 miles or more at a time, and it's way harder on the clutch than it needs to be to work through the tight stuff. A wider gear set would be very cool.

Come out west and twist through trees in a trail barely as wide as your handlebars and tell me the YZ 1st gear is low enough! Since I rarely am going anywhere 5th and pinned anways, I wonder about swapping just the WR 1st and 2nd in and leaving the rest alone... gray?

That's a thought that I've had, too, along with some other combinations of WR parts and rear gearing changes. I also thought of using the top 2 or 3 WR gears in the YZ box, but I think overall, the best setup is either going to be the full WR set, or a higher geared YZ with the bottom two WR gears.

cowboyona426

You should try some of the courses I run. Some of them work their way up through a rocky gorge and scale the rarely used backside of a mountain, then drop you out onto a dry lake. My YZ WILL go as fast as I want to on the lake bed, but I get very uncomfortable with running it at that speed for 2 miles or more at a time, and it's way harder on the clutch than it needs to be to work through the tight stuff. A wider gear set would be very cool.

That's a thought that I've had, too, along with some other combinations of WR parts and rear gearing changes. I also thought of using the top 2 or 3 WR gears in the YZ box, but I think overall, the best setup is either going to be the full WR set, or a higher geared YZ with the bottom two WR gears.

Gearing my bike taller isn't something I had ever thought of... with the lower WR 1/2 gears would you end up with a lower 1st gear or about the same as stock?My old 426 ran 13/52 gears and it worked really well for me with no FWW. Right now my 06 is stock geared and has the heavy GYT-R weight and it's still not enough, but part of that might be clutch issues (on a bike with 26 frickin' hours on it...) I want to change the oil and inspect the clutch again and see if it is beat up or if a different oil will help with the grabbiness, then I'll start looking into gearing I guess.

grayracer513

Gearing my bike taller isn't something I had ever thought of... with the lower WR 1/2 gears would you end up with a lower 1st gear or about the same as stock?

The WR low gear in your bike with stock rear gearing will yield an overall ratio of 26.35:1. To accomplish that with a YZ gear set, you would need to use a 12/61 rear gear set, if that gives you a picture.

grayracer513

I have a 2006 YZ450F and have read through the FAQ thread indicating the 2007 WR tranny will work in my bike. I'm very close to doing this but would like to hear from somebody who has actually done this.

If you've done this, can you let me know so I can ask you some questions about how it affected the bike in real world applications?

cowboyona426

The WR low gear in your bike with stock rear gearing will yield an overall ratio of 26.35:1. To accomplish that with a YZ gear set, you would need to use a 12/61 rear gear set, if that gives you a picture.

grayracer513

cowboyona426

I'm thinking the WR 1st and 2nd swap is sounding better and better... seems like there isn't a lot of difference in the upper gears and since I rarely run WFO anyways I don't think the juice would be worth the squeeze for changing the whole gearset.